Good color contrast ensures text is easy to read against its background. Accessibility guidelines (WCAG) set two standards for contrast:

• Level AA: Text needs a 4.5:1 contrast ratio, or 3.0:1 for large text (like headings).
• Level AAA: Text needs a 7.0:1 contrast ratio, or 4.5:1 for large text, for maximum readability.

Large text means 14-point bold (about 18.66px) or 18-point regular (about 24px).

Check your site with tools like Colour Contrast Analyzer or Siteimprove Accessibility Checker.

Tip: Test link colors when hovered or clicked, as many tools miss these. Try swapping text and background colors on hover for clarity.